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Haematologists apply a technique to show whether leukaemia will return

Antonio Jiménez Velasco.
Antonio Jiménez Velasco. / SUR
  • The method enables early detection and means that the patient can be given treatment to stop the illness reappearing

Knowing in advance whether a patient is going to suffer from leukaemia again is key to taking early action and preventing the illness reappearing. That's why a technique which is currently being applied successfully by haematologists in Malaga to anticipate relapses in leukaemia patients is so important.

Professionals from the haematology unit at the Regional Hospital (formerly called the Carlos Haya) and the Malaga Biomedical Research Institute (Ibima) have published the results of a study which shows that, through a technique which analyses markers in blood, it is possible to predict an early relapse in leukaemia patients more quickly. This enables doctors to react faster, and maybe even prevent it from occurring.

The study has been coordinated Antonio Jiménez Velasco, head of molecular biology at the hospital's haematology laboratory. It is based on the application of the digital PCR technique (digital polymerase chain reaction) to the haematopoietic chimerism study, providing genetic markers that enable doctors to see whether or not residual cells from the illness remain following a bone marrow transplant from a compatible donor.

Detection

A haematopoietic chimerism survey through digital PCR means that residual cells can be detected in a patient with a risk of recurring leukaemia in approximately 90 per cent of cases.

"The work tried to determine what advantages are provided by the digital PCR technique compared with the conventional PCR technique in real time, regarding the prediction of relapses in patients who undergo an allogeneic transplant of haematopoietic precursors," says Jiménez Velasco.

This method has been used to determine that the application of the technique makes it possible for patients to be treated more effectively against a possible relapse, and gives them a better quality of life.

This study started from preliminary results produced by the Malaga research team, revealed at the American Human Genetics Society conference in Boston in 2013. It had used samples from eight patients and was deemed the top piece of research among more than 500 from all over the world.

"From then onwards, we continued to improve the technique and expand the number of genetic markers so we could monitor more transplant patients. We worked in conjunction with the IMEGEN (Institute of Genomic Medicine) biotechnology company on this," says Jiménez Velasco, who is also the chief researcher in the Ibima haematology and haemotherapy group. 28 patients at the hospital who had had bone marrow transplants took part in this latest stage of the project.

Therapeutic measures

Once the haemotologists have found, through this technology, that the transplant patient still has sick cells of their own as well as those from the donor, and that these grow progressively more during the monitoring period compared with the healthy cells, they take therapeutic measures such as a reduction of immunosuppression or an infusion of lymphocytes from the donor to try to prevent relapse.

"At the moment we are working on this, and although the data is very preliminary, we can say that in approximately 50 per cent of patients it is possible to prevent the relapse if we act early," says this expert.

This technique is available at the Regional Hospital in Malaga and is used to monitor patients who have had an allogeneic transplant of haematopoietic precursors. Every year between 70 and 80 have allogeneic transplants at the hospital and the numbers are rising. The technique benefits those who have recently had transplants as well as those who are being monitored over time.

Last year the haematology laboratory at the hospital carried out 1,682 molecular haematopoietic chimerism studies.